Dusty:–Installing a small centrifugal pump on the first floor would perhaps be a better solution to the problem. You could expect an increase in pressure in direct proportion to the pumping curve data of the pump that you install and the volume that is required at any given time. Your post didnt state the number of residents on the third floor, this info would be a factor in selecting the proper sized pump. Lots of luck with your project…Bud
